JP2003138302A - Sintered member, and cutting tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sintered member of high wear resistance and long service life which can be manufactured at a low cost, and a cutting tool using the member. SOLUTION: In the sintered member 1 and the cutting tool using this member, the area occupied by hard particles 2 having the aspect ratio of at least 1.5 in the sectional structure is >=50% of the area occupied by the total hard particles contained in the section, and >=50% of the hard particles having the aspect ratio of at least 1.5 have a particle-oriented surface layer 5 in which the major axis forms an angle of within ±30 deg. to the direction orthogonal to the surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sintered member and a cutting tool, and more specifically, it has a large abrasion resistance,
The present invention relates to a sintered member that can be manufactured at low cost and a cutting tool that uses this sintered member.

[0002]

2. Description of the Related Art In a member for processing a material such as a cutting tool, or a member that slides with other members,
Increasing its wear resistance is important for improving performance and extending life.

As a member requiring such abrasion resistance, a sintered member made of cermet or cemented carbide is often used. Various improvements have been conventionally made to these sintered members for the purpose of improving their wear resistance and the like.

Japanese Unexamined Patent Publication No. 6-81071 discloses a technique relating to the shape of a cermet titanium carbonitride hard phase. According to the publication, in this cermet, by setting 50% or more of TiCN grains forming the hard dispersion layer to have an aspect ratio of 1.4 or less, high toughness is achieved while maintaining wear resistance. It is said that.

Further, in Japanese Patent Laid-Open No. 11-131170, by setting the aspect ratio of titanium carbonitride phase particles to 1.5 or more, it is possible to improve the heat resistant clutch property while maintaining the wear resistance of the cermet. The claimed invention is disclosed.

As a technique different from the above, a method of coating a hard layer with a hard material is known in order to improve wear resistance.

However, in recent cutting and the like where high speed and high precision are required, further improvement in performance such as wear resistance and machinability is required. Therefore, in the method only controlling the shape of the hard particles as described above,
It has become impossible to satisfy the demand for such improvement in performance. In addition, although the above-mentioned method of coating the hard layer can improve the abrasion resistance, it requires a coating step, and thus has the drawback of increasing the number of manufacturing steps and increasing the cost.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the drawbacks of the prior art. That is, an object of the present invention is to provide a sintered member and a cutting tool which have high wear resistance, have a long life, and can be manufactured at low cost. Another object of the present invention is to
An object of the present invention is to provide a sintered member and a cutting tool which are excellent in wear resistance without any special coating as in the prior art.

[0009]

According to the present invention for achieving the above object, in the surface layer cross-section structure, the area occupied by hard particles having an aspect ratio of at least 1.5 is contained in the surface layer cross-section. 50% or more of the area occupied by all hard particles, and 50% or more of the hard particles having an aspect ratio of at least 1.5 are ± 30 ° with respect to the direction in which the major axis is orthogonal to the surface. It is a sintered member characterized by having a particle oriented surface layer oriented so as to form an angle within the range. As a preferable aspect of the sintered member, the particle oriented surface layer has a thickness of at least 2 μm.
m, the sintered member is formed of cermet or cemented carbide, the sintered member is an insert or an engine component, the sintered member is an insert, and the particle orientation surface layer Surface forms the flank.

Yet another invention is a cutting tool comprising the insert and a tool body capable of mounting the sintered member thereof.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A sintered member according to the present invention is shown in FIG.
Will be explained. FIG. 1 is a schematic explanatory view schematically showing a partial surface layer sectional structure of a sintered member 1 which is a specific example of the sintered member according to the present invention.

The sintered member 1 is a member in which the wear resistance performance is further improved by controlling the hard phase structure of the surface portion thereof. Wear is due to wear of hard particles,
There is abrasion due to shedding of particles. The sintered member 1 has large wear resistance performance by suppressing particle abrasion, that is, abrasion caused by particles detaching from the surface of the member.

The sintered member 1 can be formed of cermet or the like. The structure of this cermet is mainly formed by a binder phase and a hard phase mainly composed of a metal carbonitride phase. Examples of the substance forming the binder phase include N
i and Co can be mentioned. Examples of the metal forming the carbonitride metal phase include Ti, V, Cr, Zr,
Nb, Mo, Hf, Ta and W can be mentioned.
As the carbonitride metal, TiC and TiN are particularly preferable because they have high wear resistance, welding resistance, oxidation resistance, plastic deformation resistance, and heat resistance. Examples of the cermet, for example, _{TiC-Ni-Mo (Mo 2} C) based cermet, and T
iC-TiN-Ni-Mo ( Mo 2 C) based titanium-based cermet such as cermet, and can be exemplified _Cr 3 _C 2 -Ni cermet. Among these, titanium-based cermets are preferable, and TiC-TiN-Ni-Mo is particularly preferable.
(Mo ₂ C) -based cermet is suitable. The titanium-based cermet for example TiC-TiN-Ni-Mo ( Mo 2 C)
The system cermet may contain WC and Co.
Such titanium-based cermets such as TiC-TiN-
The Ni—Mo (Mo ₂ C) cermet is further improved in oxidation resistance, compositional deformation resistance, and heat resistance while taking advantage of the wear resistance and welding resistance of the TiC group.

The hard phase is composed of a large number of hard particles. As shown in FIG. 1, in the cermet structure, that is, the structure of the sintered member 1, a large number of hard particles 2 are aggregated to form a hard phase 3, and a hard phase 2 exists between the hard particles 2. ing.

The hard particles can have various shapes.
For each of the hard particles, the aspect ratio can be determined from the maximum diameter and the minimum diameter. For example, for a hard particle having a shape shown in the surface layer cross section as shown in FIG. 2, the hard particle was drawn so as to be in contact with the hard particle and not to cross the hard particle. The maximum value of the distance between parallel lines of the book is the maximum diameter Dma
x, and its minimum value is the minimum diameter Dmin, and Dmax / Dmin
Is the aspect ratio.

As shown in FIG. 1, the sintered member 1 has a grain oriented surface layer 5 and a body portion 6. The grain oriented surface layer 5 is a portion that realizes high wear resistance of the sintered member 1. In the surface layer cross-section structure of the particle oriented surface layer 5, the area occupied by hard particles having an aspect ratio of at least 1.5 is 50% or more of the area occupied by all the hard particles contained in the surface layer cross section. There is a part.

That is, the grain oriented surface layer 5 has long hard particles 7 which are hard particles having an aspect ratio of at least 1.5 appearing in the texture of the surface layer cross section shown in FIG. Long hard particles 7 appearing in the cross section of the particle-oriented surface layer 5
Is the total area of all the hard particles appearing in the surface layer cross section, that is, the total area of the long hard particles 7 and the total area of the short hard particles 8 which are hard particles having an aspect ratio of less than 1.5. It is 50% or more.

In the grain-oriented surface layer 5, 50% or more of the hard particles having an aspect ratio of at least 1.5 in the cross-sectional surface layer structure have a major axis perpendicular to the surface. It is a portion oriented so as to form an angle within ± 30 °.

That is, in the cross section of the grain oriented surface layer 5 shown in FIG. 1, 50% or more of the long hard particles 7 appearing in the cross section of the surface layer have long hard particles 7 as shown in FIG. In addition, the angle formed by the major axis 11 with respect to the virtual line 10 indicating the direction orthogonal to the surface 9 of the sintered member 1 is ± 3.
It is within 0 °. Here, “long axis” means D in FIG.
Of the straight lines orthogonal to the two parallel lines giving max, the straight line having the largest length passing through the hard particles.

When the long hard particles have an aspect ratio of at least 1.5 in the sintered member 1, such long hard particles have a surface area retained between the binder phase 4 and other hard particles. The reason for this is that it is difficult to shed particles because it is large, and short hard particles having an aspect ratio of less than 1.5 have a small surface area and it is difficult to prevent the particles from shattering.

In the sintered member 1, the ratio of the area occupied by the long hard particles 7 in the cross section of the grain oriented surface layer 5 to the area occupied by all the hard particles in the surface layer is required to be 50% or more. Is less than 50%, the desired effect of suppressing shedding is small. The ratio of the area occupied by the long hard particles to the area occupied by all the hard particles in the surface layer in the cross section of the grain oriented surface layer 5 is particularly preferably 55 to 70%.

In the sintered member 1, the long hard particles 7 having an aspect ratio of at least 1.5 are oriented such that the major axis forms an angle of ± 30 ° with respect to the direction orthogonal to the surface 9. If such a long hard particle 7 is present,
And since it is deeply embedded between other hard particles, it becomes difficult to shed particles. Further, in order to shed such long hard particles 7 from the particle oriented surface layer 5,
The force needs to act upward at an angle close to a right angle to the surface 9, but when abrasion occurs, the force acting in such a direction is usually small, so that such long hard particles 7 are difficult to shed. If the angle exceeds ± 30 °, the effect is reduced and the hard particles are easily shed.

In the sintered member 1, 50% or more of the long hard particles 7 contained in the grain oriented surface layer 5 have a major axis whose angle is within ± 30 ° with respect to the direction orthogonal to the surface 9. The reason why the long hard particles oriented in such a manner are required to be less than 50% is that the desired effect of suppressing grain shedding cannot be obtained.

The aspect ratio of the hard particles 2, the ratio of the area occupied by the long hard particles 7 in the cross section of the grain oriented surface layer 5 to the area occupied by the hard particles of all surface layers, and the long hard particles in the direction orthogonal to the surface 9. The angle formed by the long axis of 7 and the proportion of the long hard particles 7 oriented as described above can be obtained by electron microscope photography of the cross section of the particle oriented surface layer 5, for example, a tissue image as shown in FIG. Can be obtained from

The thickness of the grain oriented surface layer 5 is not particularly limited as long as the grain oriented surface layer 5 satisfies the above conditions.
The thickness is preferably at least 2 μm, more preferably 3 to 6 μm. When the thickness is less than 2 μm, the number of long-hard particles satisfying the above conditions contained in the particle oriented surface layer 5 is small, and the sufficient effect of suppressing shedding may not be obtained. The thickness of the grain oriented surface layer 5 does not have to be uniform, and may vary depending on the site as long as the above-mentioned conditions are satisfied.

The sintered member 1 has the grain oriented surface layer 5, but it is not necessary that all of the surface layers are the grain oriented surface layer 5, and if the predetermined portion of the surface layer is the grain oriented surface layer 5. Good. Further, the surface of the sintered member 1 which is required to have wear resistance may be a grain oriented surface layer.

The main body portion 6 is a portion that holds the grain oriented surface layer 5, and is a portion that ensures the strength of the entire sintered member 1. The main body portion 6 is also a portion of the sintered member 1 other than the grain oriented surface layer 5. Therefore, when there is a surface layer other than the grain oriented surface layer 5 in the sintered member 1, the surface layer other than the grain oriented surface layer 5 is a part of the main body portion 6.

The structure of the main body 6 is not particularly limited as long as the main body 6 has the usual properties as a cermet. In the structure of the main body 6, for example, the abundance ratio of the long hard particles and the short hard particles and the direction of the long axis of the long hard particles are arbitrary.

Regarding the size and shape of the sintered member 1,
There is no particular limitation as long as the function of the sintered member 1 can be ensured, and it can be appropriately determined depending on the type of the sintered member 1 and the purpose of use.

The sintered member 1 is made of cermet, but the sintered member according to the present invention may be made of a sintered material other than cermet, for example, cemented carbide. When a cemented carbide is used for the sintered member according to the present invention, the substance forming the binder phase may be, for example, Fe or Co.
And Ni, and examples of the metal forming the metal carbide phase include W, Ti, Ta and Nb. As the metal carbide, WC is particularly preferable because it has high hardness and high toughness. Examples of the cemented carbide include WC-Co type and WC-TiC-Co.
System, WC-TaC-Co system and WC-TiC-Ta (N
b) C-Co type can be mentioned.

The sintered member 1 operates as follows. Since the sintered member 1 has high abrasion resistance in the grain oriented surface layer 5, it is used so as to come into contact with another member on the surface of the grain oriented surface layer 5. For example, if the sintered member 1 is a cutting member, its flank surface is used so as to be formed on the surface of the grain oriented surface layer 5, and if the sintered member 1 is a bearing, the surface on which the sliding member slides. Are used to form on the surface of the grain oriented surface layer 5.

When the sintered member 1 and other members slide on each other while the sintered member 1 is in contact with another member on the surface of the particle oriented surface layer 5, the particle oriented surface layer 5 The surface receives friction from the member.

In the grain-oriented surface layer 5, in the surface layer cross-section structure, the area occupied by the long hard particles 7 is 50% of the area occupied by all the surface layer hard particles contained in the surface layer cross section.
That is all. That is, in the hard particles forming the particle oriented surface layer 5, long hard particles having an aspect ratio of at least 1.5 are present in a high proportion. Such long hard particles have a larger surface area retained between the binder phase 4 and the other hard particles than the short hard particles, and thus are hard to separate from the particle oriented surface layer 5. Therefore, the sintered member 1
In the above, since the long hard particles 7 do not easily separate from the particle oriented surface layer 5 even if they slide with each other as described above, wear of the hard particles due to shedding is small.

The grain oriented surface layer 5 has a cross-sectional surface layer structure such that 50% or more of the long hard particles 7 form an angle within ± 30 ° with respect to the direction in which the major axis is orthogonal to the surface. Oriented. That is, about half or more of the long hard particles 7 contained in the particle oriented surface layer 5 exist such that the major axis thereof has an angle close to a right angle with respect to the surface 9 of the particle oriented surface layer 5. The part of the long hard particles 7 far from the surface 9 reaches the deep part of the particle oriented surface layer 5. Therefore, in the sintered member 1, even if the other members slide with each other as described above, the long hard particles 7 are unlikely to separate from the particle oriented surface layer 5,
Little wear due to shedding of hard particles.

Further, in order to shed particles from the particle-oriented surface layer 5, the long-hard particles 7 whose major axis exists so as to have an angle close to a right angle with respect to the surface 9 of the particle-oriented surface layer 5, The force needs to act upward on the particles 7 at an angle close to a right angle to the surface 9. When the sintered member 1 is abraded by sliding between the sintered member 1 and another member, the force acting in such a direction on the hard particles contained in the sintered member 1 is usually small. The longer hard particles 7 are present in the sintered member 1 at an angle closer to a right angle with respect to the surface 9 of the sintered member 1, the more difficult it is to separate from the surface. Therefore, in the sintered member 1, even if the other members slide with each other as described above, the long hard particles 7 are unlikely to be separated from the particle oriented surface layer 5, so that the hard particles are shattered. Little wear due to.

As described above, the sintered member 1 has a small amount of wear due to the shedding of hard particles, and thus has a large wear resistance.

The sintered member 1 can be manufactured by a known cermet manufacturing method by appropriately setting the firing temperature, the cooling rate, the type of gas contained in the manufacturing atmosphere, the pressure thereof, and the like.

As a raw material for forming the sintered member 1, a usual raw material used for forming cermet and cemented carbide can be adopted. Usually, this sintered member can be obtained by sintering a raw material powder. As the raw material powder, usual raw materials for forming cermet and cemented carbide are used. The firing temperature may be, for example, 1400 to 1650 ° C, preferably 1500 to 1600 ° C.

The cooling rate is, for example, -2.5 to -0.
5 ° C./min, preferably −2 to −1 ° C.
/ Min.

Examples of the types of gas contained in the manufacturing atmosphere include nitrogen and argon,
Nitrogen is preferred.

The pressure of the gas is, for example, 1.0 to 6.0.
It may be kPa, preferably 1.5 to 4 kPa. The peculiar particle oriented surface layer existing on the surface of the sintered member according to the present invention has a surface in the sintered member which is obtained by performing sintering and cooling under the above sintering conditions even if the raw material particles are substantially spherical particles. Nearby spherical particles grow in one direction,
It is thought that it is formed as a result.

The sintered member according to the present invention can be widely used in civil engineering construction machines, railway vehicles, automobiles, aircrafts, ships, machine tools and the like where abrasion resistance is required. Such applications include, for example, inserts, cutting tools, engine parts such as cylinders and pistons, and the like.

The insert which is the sintered member according to the present invention can be formed into various shapes according to the purpose. FIG. 4 shows an insert 12 which is a specific example of the insert which is the sintered member according to the present invention.

The insert 12 shown in FIG. 4 has a rectangular parallelepiped shape. One corner is the corner 13.
Of the three sides forming the corner 13, the longest side 14 is the cutting edge 17, and the second longest side 15 is the cutting edge 18. Of the faces of the rectangular parallelepiped, the face having sides 14 and 15 as two sides is the rake face 19,
The surface having the side 14 and the shortest side 16 of the three sides as the two sides is the flank 20, and the surface having the sides 15 and 16 as the two sides is the flank 21.

In the insert 12, the flanks 20 and 21 are formed by the surface of the grain oriented surface layer.

The method of using the insert 12 is the same as that of a normal insert. The insert 12 can be manufactured similarly to a conventional insert. The flank of the insert wears due to a strong force exerted by the work material during cutting. In the insert 12, since the flanks 20 and 21 are formed by the surface of the grain oriented surface layer, as described in the explanation of the operation of the sintered member 1, the flank 20 and the flank 21 receive a strong force from the work material. Also, the wear is small. Therefore, the insert 12 has a long life.

The sintered member according to the present invention can be used as a cutting tool by itself, but can also be used as an insert. A cutting tool can be manufactured by mounting the insert on the tool body. Examples of the cutting tool include a cutting tool, a drill, a milling cutter, and a broach. The insert according to the present invention can be mounted on the tool body in the same manner as a conventional insert.

FIG. 5 shows an example of the cutting tool. Figure 5
FIG. 6 is a perspective view of the cutting tool 22. The bite 22 includes an insert 23 according to the present invention and a holder 24 that is a tool body.
And.

In the insert according to the present invention used in the example of the cutting tool, the surface serving as the flank is formed by the surface of the grain oriented surface layer. The operation of the cutting tool is the same as that of the sintered member 1 and the insert 12.
It is similar to the operation shown in.

[0050]

EXAMPLES Hereinafter, the sintered member according to the present invention will be specifically described by way of examples.

(1) Preparation of sintered body According to the composition shown in Table 1, titanium carbide powder and titanium nitride powder having an average particle diameter of 1 μm (titanium carbide / titanium nitride = 1/1 (weight ratio)), Tungsten carbide powder having an average particle size of 1.5 μm, molybdenum carbide (Mo ₂ C) powder having an average particle size of 3 μm, niobium carbide powder having an average particle size of 1 μm,
Ni powder having an average particle size of 3 μm and C having an average particle size of 3 μm
o powder, or the titanium carbide powder and titanium nitride powder, the tungsten carbide powder, the niobium carbide powder, the Ni powder, the Co powder and an average particle size of 1.5.
μm tantalum carbide powder was blended and mixed with acetone as a solvent by a ball mill for 18 hours. The powder after mixing was dried and then kneaded by adding a microwax-based binder. Next, the kneaded product was press-molded at a pressure of 200 MPa to have a predetermined shape, and then dewaxed.

The obtained molded body was subjected to 145 in a nitrogen atmosphere.
Firing was performed by holding at 0 to 1650 ° C. for 60 minutes. Then, it was cooled to (maximum keep temperature −100) ° C. at the cooling rate and nitrogen pressure shown in Table 1. Through the above, cermet sintered bodies A to H were obtained.

(2) Observation of Section by Electron Microscope Sintered bodies A to H were cut, the section was mirror-polished, and then a structure photograph of the section was obtained by a scanning electron microscope. From this microstructure photograph, the ratio of the area of the hard particles having an aspect ratio of 1.5 or more existing in the surface layer to the area of the entire hard phase contained in the surface layer was measured, and the value was determined to be the long hard particle existence ratio. And

From this microstructure photograph, it was confirmed that the major axis forms an angle within ± 30 ° with respect to the direction orthogonal to the surface with respect to the total number of hard particles having an aspect ratio of 1.5 or more existing in the surface layer. The number of the hard particles oriented in the above was measured, and this value was defined as the ratio of oriented hard particles.

The results obtained from the above measurements are shown in Table 2. From the long hard particle existence ratio and the oriented hard particle ratio shown in Table 2, the sintered bodies A, B and G have the particle oriented surface layer, and the sintered bodies C to F and H are the above. It was confirmed that it did not have a grain oriented surface layer. Sintered body E
For the above, from the structure photograph, with respect to the total area of the hard phase contained in the surface layer, the ratio of the area of the hard particles having an aspect ratio of 1.4 or more present in the surface layer is measured,
The value was defined as 1.4-long hard particle existence ratio. Regarding the sintered body E, from the above structure photograph, an angle within ± 30 ° of the major axis with respect to the direction orthogonal to the surface with respect to the total number of hard particles having an aspect ratio of 1.4 or more existing in the surface layer is shown. The number of the hard particles oriented so as to be formed was measured, and this value was defined as 1.4-oriented hard particle ratio. These results are also shown in Table 2.

(3) Cutting test Sintered bodies A to F were ground and subjected to SNMN1 according to the ISO standard.
A cutting tool having a shape defined as 20308 was created. The sintered bodies G and H were polished to prepare a cutting tool having a shape defined as SNGN120308 in the 1SO standard. The shapes of these cutting tools are shown in FIGS. FIG. 6 is a perspective view of the cutting tool 28. FIG. 7 is a schematic side sectional view of the cutting tool 28. Figure 8
FIG. 7 is a partially enlarged perspective view of a portion surrounded by a dotted line in FIG. 6. The cutting tool 28 has a thickness of about 3.18 mm and a side of about 1
It has a flat prismatic shape with a substantially square section of 2.7 mm, and the radius of the rounded corner 29 is about 0.8 mm. Chamfered chamfer on the edge 30
As shown in FIG. 7, the width t on the main surface 31 side is about 0.
It was formed so that the inclination angle θ with respect to the main surface 31 was 1 mm and about 25 °.

The cutting tools according to the present invention were obtained from the sintered bodies A, B and G, and the cutting tools other than the cutting tool according to the present invention were obtained from the sintered bodies C to F and H. Sintered body A,
In B and G, the cutting tool was prepared so that the flank surface was formed by the surface of the grain oriented surface layer.

A cutting test was carried out using these cutting tools. The rod-shaped work material 35 having the shape shown in FIG. 9 is rotated around the axis, and the cutting tool 28 is brought into contact with the outer peripheral surface thereof as shown in FIG. Are used as flanks, the cutting tools obtained from the sintered bodies A to F are cut under the following cutting conditions 1, and the cutting tools obtained from the sintered bodies G to H are cut under the following cutting conditions 2. The outer peripheral surface of the work material was continuously wet-cut. Figure 10
In, 33 is a lateral flank and 34 is a front flank.

(Cutting condition 1) Work material: SNCM439H Cutting speed: 250 m / min Depth of cut: 1.5 mm Feed: 0.15 mm / rev Cutting time: 8 min Cutting method: Wet tool shape; SNMN120308 (Chamfer;
0.1 × 25 °) (Cutting condition 2) Work material; SNCM439H Cutting speed; 180 m / min Depth of cut; 1.5 mm feed; 0.2 mm / rev Cutting time; 8 min Cutting method; Wet tool shape; SNMN120308 (Chamfer) ;
After cutting, the flank wear amount Vn of the cutting edge of the tool (wearing height in the turning direction on the side flank 33 side: see FIG. 11) was measured. The results are shown in Table 2.

[0060]

[Table 1]

[0061]

[Table 2]

[0062]

EFFECTS OF THE INVENTION Since the sintered member according to the present invention has the grain oriented surface layer, shedding of hard particles is suppressed and abrasion resistance is great. When this sintered member is used as an insert or a cutting tool, it exhibits excellent wear resistance against a wide range of work materials such as low carbon steel, alloy steel, and stainless steel.

Since the sintered member according to the present invention does not require a coating step in its manufacturing process, it can be manufactured at a low cost with a small number of manufacturing steps.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a partial surface layer cross-section structure of a sintered member 1.

FIG. 2 is an explanatory diagram for defining a maximum diameter and a minimum diameter of particles for obtaining an aspect ratio.

FIG. 3 is an explanatory diagram showing an angle formed by a major axis 11 of the long hard particles 7 with respect to a line 10 indicating a direction orthogonal to the surface 9 of the sintered member 1.

FIG. 4 is a perspective view of the insert 12.

FIG. 5 is a perspective view of a cutting tool 22.

FIG. 6 is a perspective view of a cutting tool 28.

FIG. 7 is a schematic side sectional view of a cutting tool 28.

FIG. 8 is a partially enlarged perspective view of the cutting tool 28.

FIG. 9 is an explanatory diagram showing an outline of a cutting test.

FIG. 10 is an explanatory diagram showing an outline of a cutting test.

FIG. 11 is an explanatory diagram showing how to obtain a flank wear amount.

FIG. 12 is an electron micrograph which is a drawing-substitute photograph showing a cross-section of a surface layer of a sintered member having a grain-oriented surface layer.

[Explanation of symbols]

1 ... Sintered member, 2 ... Hard particles, 3 ... Hard phase, 4 ...
・ Binder phase, 5 ・ ・ Particle orientation surface layer, 6 ・ ・ Main body, 7 ・
・ Long particle orientation surface layer, 8 ・ ・ Short particle orientation surface layer, 9 ・ ・
Surface, 10 ... Line, 11 ... Long axis, 12 ... Insert, 13 ... Corner, 14 ... Side, 15 ... Side, 16
..Side, 17 ... Cutting edge, 18 ... Cutting edge, 19 ... Scooping surface, 20 Flank surface, 21 Flank surface, 22 bit Tool, 23 ... Insert, 24 ... Holder, 28・ ・
Cutting tool, 29..corner part, 30..edge part, 3
1 ・ ・ Main surface, 32 ・ ・ Side surface, 33 ・ ・ Side flank, 34 ・
・ Front flank, 35 ・ ・ Work material, Dmax ・ ・ Maximum diameter, Dmin
..Minimum diameter, t..width, θ..inclination angle, Vn..flank wear amount

Claims (6)

[Claims] 1. An area occupied by hard particles having an aspect ratio of at least 1.5 in the surface layer cross-section structure is 50% or more of the area occupied by all hard particles contained in the surface layer cross section, and At least 50% of the hard particles having an aspect ratio of at least 1.5 have a particle orientation surface layer oriented such that the major axis forms an angle within ± 30 ° with respect to the direction orthogonal to the surface. A sintered member characterized by the above. 2. The sintered member according to claim 1, wherein the grain oriented surface layer has a thickness of at least 2 μm. 3. The sintered member according to claim 1, which is made of cermet or cemented carbide. 4. The sintered member according to claim 1, which is an insert or an engine part. 5. The sintered member according to claim 1, which is an insert, wherein the surface of the grain oriented surface layer forms a flank thereof. 6. A cutting tool comprising: the sintered member according to claim 5; and a tool body to which the sintered member can be attached.